In large electronic data-processing systems, the individual electronic components, such as, for example, a plurality of servers, are stored in cabinets or racks, in order to guarantee an ordered installation and cabling of the individual components. In addition, the climate is controlled in racks or cabinets for such electronic components that is, the waste power generated by the components in the form of heat energy is dissipated with suitable means. In the following, the term rack is used both for closed cabinets and also for open shelves, in which the individual components are stored. The waste power is generated mainly by electronic parts of the individual components. In modern data-processing systems, the predominant portion of the waste power is generated by microprocessors. The waste power of a processor has been up to now on the order of magnitude of ca. 100 W. Waste power in this range was dissipated with processor fans, that is, a combination of a metallic heat sink and a fan component, from the processor into the interior of the housing of the server or the electronic components, from there into the interior of the (preferably closed) rack, and then to the outside air surrounding the rack. To this is added the waste power in the form of heat discharged from other assemblies and parts of the individual electronic components, such as power supply parts, drives, etc., that is, from a plurality of individual electronic components, which, taken by themselves, definitely discharge a relatively small amount of waste power, so that a separate cooling of these electronic components is not worthwhile, wherein these small waste powers can add up to values from 100 to 150 W and more per electronic component. Therefore, in addition to the processor fans, additional fans are usually necessary in order to dissipate all of the waste heat generated in the housing of the electronic component. For server racks, which can store up to 50 individual servers each possibly with several processors, a total waste power of 10 kW to 12.5 kW per rack is thus already generated.
For coming generations of electronic components, an increase of the heat waste power discharged by individual electronic components, such as microprocessors, from 150 to 200 W and more is expected. In a rack, for example, with up to 50 servers, including the additional waste power of 100 to 150 W per electronic component, this leads to a total waste power of up to 17.5 kW and more per rack. Such high waste powers in the form of heat can no longer be managed with reasonable expense just by air as the heat carrier medium.
For individual electronic components, such as servers, it is known to cool electronic components, especially microprocessors, which, by themselves, generate a large amount of waste power, by heat sinks carrying a flow of a liquid cooling medium, for example, water, instead of combinations of heat sinks and fans. Thus, only the heat waste power generated by the other assemblies and components that are not cooled individually must still be dissipated by means of air as the medium.
Both for cooling devices, which comprise a heat sink and a fan, and also for cooling devices with a heat sink carrying a flow of a liquid heat carrier medium, there is the problem that this must be mounted with the best possible heat conduction on the electronic component to be cooled, usually a component with a semiconductor chip. For guaranteeing good heat transfer, usually a heat-conductive paste is used between the thermal interface of the component and the heat sink. In addition, a sufficient contact pressure is necessary. If the heat sink has to be removed, for example, because the fan integrated into the heat sink is defective or because compactly arranged assemblies or parts must be manipulated within the narrow housing of the electronic component, then there is the risk, for each disassembly or assembly of the heat sink, that the sensitive electronic component could be damaged or destroyed.
If an electronic component is to be removed from a rack and replaced, and if a known cooling device is used for this electronic component with a liquid heat carrier medium or coolant, then either the supply lines for the coolant must be separated, preferably at connectors, or the entire cooling device must be removed from the electronic component to be cooled and the risk of damaging this component must be taken into account. However, when the supply lines are separated, there is also a considerable risk of damaging this electronic component or adjacent electronic components, even if only a small amount of coolant leaks out. This applies especially when the electronic component is to be replaced during the operation of the other electronic components (hot plugging).
Starting with this state of the art, the invention is based on the problem of creating a cooling device for an electronic component, especially for a microprocessor, in which the actual heat sink can be mounted and removed easily, quickly, and without the risk of damaging or destroying the electronic component to be cooled. In addition, the invention is based on the problem of creating a rack for storing several electronic components, such as servers for data-processing systems, under the use of such cooling devices, which are cooled by a liquid heat carrier medium.